/* *****************************************************************
    MESQUITE -- The Mesh Quality Improvement Toolkit

    Copyright 2006 Lawrence Livermore National Laboratory.  Under
    the terms of Contract B545069 with the University of Wisconsin --
    Madison, Lawrence Livermore National Laboratory retains certain
    rights in this software.

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    (lgpl.txt) along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    (2006) kraftche@cae.wisc.edu

  ***************************************************************** */

#ifndef MSQ_OFEVALUATOR_HPP
#define MSQ_OFEVALUATOR_HPP

/** \file OFEvaluator.hpp
 *  \brief
 *  \author Jason Kraftcheck
 */

#include <vector>

#include "Vector3D.hpp"
#include "ObjectiveFunction.hpp"

namespace MBMesquite
{

class MsqError;
class Mesh;
class MeshDomain;
class PatchData;
class MsqHessian;
class PatchSet;

/**\brief Evaluate objective function
 *
 * This class handles the details of the differences between
 * Nash and block coordinate descent methods for evaluation
 * of the objective function, such that solvers need only
 * interact with this interface and need not be aware of the
 * Nash vs. BCD details.
 */
class MESQUITE_EXPORT OFEvaluator
{
  public:
    /**\brief Constructor
     *\param of The objective function (may be NULL for Laplacian-type solvers)
     *\param Nash True for Nash-type solutions, false for
     *       block coordinate descent.
     */
    OFEvaluator( ObjectiveFunction* of );

    void initialize_queue( MeshDomainAssoc* mesh_and_domain, const Settings* settings, MsqError& err );

    /**\brief Initialize OFEvaluator
     *
     * For a Nash-type algorithm, this method will initialize
     * some member variables.  For a block coordinate descent
     * solution, this method will calculate an initial value
     * of the objective function for the mesh.
     *
     *\param mesh The active mesh
     */
    bool initialize( MeshDomainAssoc* mesh_and_domain, const Settings* settings, PatchSet* patches, MsqError& err );

    /**\brief Update accumulated values for changes to vertex positions
     *        in a patch.
     *
     * For a block coordinate descent solution, this method calculates
     * the updated global objective function value for any modifications
     * to the passed patch, as made by the solver.  The change to
     * the current patch state is considered relative to that of the
     * previous patch passed to any of the update methods, except when
     * the reset() method has been called by the solver to indicate
     * that a new inner iteration is starting.
     *
     * For a Nash-type solution, this method simply returns the evaluation
     * of the objective funtion for the local patch.  The behavior is identical
     * to calling the evaluate() method.
     *
     *\param pd  The mesh patch
     *\param value Output, the value of the objective function.
     */
    bool update( PatchData& pd, double& value, MsqError& err );

    /**\brief Update accumulated values for changes to vertex positions
     *        in a patch.
     *
     * For a block coordinate descent solution, this method calculates
     * the updated global objective function value for any modifications
     * to the passed patch, as made by the solver.  The change to
     * the current patch state is considered relative to that of the
     * previous patch passed to any of the update methods, except when
     * the reset() method has been called by the solver to indicate
     * that a new inner iteration is starting.
     *
     * For a Nash-type solution, this method simply returns the evaluation
     * of the objective funtion for the local patch.  The behavior is identical
     * to calling the evaluate() method.
     *
     *\param pd  The mesh patch
     *\param value Output, the value of the objective function.
     *\param grad Output, the gradient of the objective function
     *             with respect to each FREE vertex in the patch.
     */
    bool update( PatchData& pd, double& value, std::vector< Vector3D >& grad, MsqError& err );

    /**\brief Update accumulated values for changes to vertex positions
     *        in a patch.
     *
     * For a block coordinate descent solution, this method calculates
     * the updated global objective function value for any modifications
     * to the passed patch, as made by the solver.  The change to
     * the current patch state is considered relative to that of the
     * previous patch passed to any of the update methods, except when
     * the reset() method has been called by the solver to indicate
     * that a new inner iteration is starting.
     *
     * For a Nash-type solution, this method simply returns the evaluation
     * of the objective funtion for the local patch.  The behavior is identical
     * to calling the evaluate() method.
     *
     *\param pd  The mesh patch
     *\param value Output, the value of the objective function.
     *\param grad Output, the gradient of the objective function
     *             with respect to each FREE vertex in the patch.
     *\param Hessian_diag_blocks Output, 3x3 submatrices along diagonal of
     *                           Hessian of objective function
     */
    bool update( PatchData& pd,
                 double& value,
                 std::vector< Vector3D >& grad,
                 std::vector< SymMatrix3D >& Hessian_diag_blocks,
                 MsqError& err );

    /**\brief Update accumulated values for changes to vertex positions
     *        in a patch.
     *
     * For a block coordinate descent solution, this method calculates
     * the updated global objective function value for any modifications
     * to the passed patch, as made by the solver.  The change to
     * the current patch state is considered relative to that of the
     * previous patch passed to any of the update methods, except when
     * the reset() method has been called by the solver to indicate
     * that a new inner iteration is starting.
     *
     * For a Nash-type solution, this method simply returns the evaluation
     * of the objective funtion for the local patch.  The behavior is identical
     * to calling the evaluate() method.
     *
     *\param pd  The mesh patch
     *\param value Output, the value of the objective function.
     *\param grad Output, the gradient of the objective function
     *             with respect to each FREE vertex in the patch.
     *\param Hessian Output, the Hessian of the objective function.
     */
    bool update( PatchData& pd, double& value, std::vector< Vector3D >& grad, MsqHessian& Hessian, MsqError& err );

    /**\brief Check if doing Nash game algorithm.*/
    bool is_nash_game() const
    {
        return !doBCD;
    }

    /**\brief Do Nash game algorithm.*/
    void do_nash_game()
    {
        doBCD = false;
    }

    /**\brief Check if doing block coordinate descent algorithm */
    bool is_block_coordinate_descent() const
    {
        return doBCD;
    }

    /**\brief Do block coordinate descent algorithm.*/
    void do_block_coordinate_descent()
    {
        doBCD = true;
    }

    /**\brief Evaluate the objective function without changing any
     *        accumulated values.
     *
     * Evaluate the objective function for the specified patch
     * (or for the change to the specified patch for BCD).  This
     * method does not change any internal state or accumulated
     * values.  It is provided for FeasibleNewton and other solvers
     * that need to obtain an OF value for some intermediate or
     * temporary set of vertex positions.
     *
     *\param pd  The mesh patch
     *\param value Output, the value of the objective function.
     */
    bool evaluate( PatchData& pd, double& value, MsqError& err ) const;

    /**\brief Evaluate the objective function without changing any
     *        accumulated values.
     *
     * Evaluate the objective function for the specified patch
     * (or for the change to the specified patch for BCD).  This
     * method does not change any internal state or accumulated
     * values.  It is provided for FeasibleNewton and other solvers
     * that need to obtain an OF value for some intermediate or
     * temporary set of vertex positions.
     *
     *\param pd  The mesh patch
     *\param value Output, the value of the objective function.
     *\param grad Output, the gradient of the objective function
     *             with respect to each FREE vertex in the patch.
     */
    bool evaluate( PatchData& pd, double& value, std::vector< Vector3D >& grad, MsqError& err ) const;

    /**\brief Evaluate the objective function without changing any
     *        accumulated values.
     *
     * Evaluate the objective function for the specified patch
     * (or for the change to the specified patch for BCD).  This
     * method does not change any internal state or accumulated
     * values.  It is provided for FeasibleNewton and other solvers
     * that need to obtain an OF value for some intermediate or
     * temporary set of vertex positions.
     *
     *\param pd  The mesh patch
     *\param value Output, the value of the objective function.
     *\param grad Output, the gradient of the objective function
     *             with respect to each FREE vertex in the patch.
     *\param Hessian_diag_blocks Output, 3x3 submatrices along diagonal of
     *                           Hessian of objective function
     */
    bool evaluate( PatchData& pd,
                   double& value,
                   std::vector< Vector3D >& grad,
                   std::vector< SymMatrix3D >& Hessian_diag_blocks,
                   MsqError& err ) const;

    /**\brief Evaluate the objective function without changing any
     *        accumulated values.
     *
     * Evaluate the objective function for the specified patch
     * (or for the change to the specified patch for BCD).  This
     * method does not change any internal state or accumulated
     * values.  It is provided for FeasibleNewton and other solvers
     * that need to obtain an OF value for some intermediate or
     * temporary set of vertex positions.
     *
     *\param pd  The mesh patch
     *\param value Output, the value of the objective function.
     *\param grad Output, the gradient of the objective function
     *             with respect to each FREE vertex in the patch.
     *\param Hessian Output, the Hessian of the objective function.
     */
    bool evaluate( PatchData& pd,
                   double& value,
                   std::vector< Vector3D >& grad,
                   MsqHessian& Hessian,
                   MsqError& err ) const;

    /**\brief Reset for next inner iteration
     *
     * The control code for the vertex mover is responsible for
     * calling this method before the beginning of each inner
     * solver iteration so the necessary internal state can be
     * updated for the correct behavior of the first call to
     * the update() method for block coordinate descent algorithms.
     */
    bool reset();

    /**\brief Get ObjectiveFunction pointer */
    inline ObjectiveFunction* get_objective_function() const
    {
        return this->OF;
    }

    /**\brief Check if we have an objective function */
    inline bool have_objective_function() const
    {
        return 0 != get_objective_function();
    }

  private:
    /**\brief Disallow copying*/
    OFEvaluator( const OFEvaluator& );

    /**\brief Disallow assignment*/
    OFEvaluator& operator=( const OFEvaluator& );

    /** The ObjectiveFunction to evaluate */
    ObjectiveFunction* const OF;

    /** Nash or BCD */
    bool doBCD;

    /** Nash vs. BCD and state of BCD data */
    ObjectiveFunction::EvalType tempType, firstType, updateType, currUpdateType;
};

}  // namespace MBMesquite

#endif
